1. Field
This disclosure relates generally to semiconductor device fabrication, and more specifically, to providing a front-end-of-line through-substrate via for application in MEMS sensor products.
2. Related Art
In semiconductor device fabrication, it is often desirable to be able to communicate signals from one surface of a substrate on which the semiconductor device is fabricated to the other surface. Such signals are communicated using through-substrate vias (TSV), which are conductive paths provided in the substrate. An example of semiconductor devices that use such TSVs are microelectromechanical devices, such as accelerometers, pressure sensors, and gyroscopes, and chip scale packages.
Typically, TSVs have been made by either drilling and depositing conductive material in the hole made in the substrate, or have been made by using a conductive substrate (e.g., highly-doped silicon) and electrically isolating a region of the conductive substrate to act as a TSV. These methods have drawbacks in that they either add steps to the process for fabricating the semiconductor device, use a higher cost, highly doped substrate as a starting material, or utilize geometries that compromise performance.
It is therefore desirable to be able to form TSVs in a way that uses less expensive, non-doped substrates, and can be used with minimal disruption to fabrication processes.
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